I've found a vendor who has a gas tank sending unit that I think will fit my '48 1-Ton dually. One of the model applications he lists is ES, which the Master Parts Catalogue shows is for a '47 model, the E for 1947 and the S for 1-Ton. However, he says that the sender is not listed for my '48, model FS, the F for 1948 and the S for 1-ton. If I'm reading the catalogue correctly both the '47 and '48 use the same tank, part number 3847323, 18 gallons, installed between the frames. Shouldn't the same sender work for both? Although I can find many of the gas tank parts in the catalogue, I can't seem to find the sending unit to see what the applications are. Can anyone point out where the sending unit is listed in the Master Parts Catalogue? Thanks, Jim